I would like to shoot some Ilford SFX 200 with my Pressman. I think I'll have to make some focus corrections to get sharp image. How can I calculate it?
The lens is 100 mm Tessar with a 720 nm filter._________________MFRFFC

FOCUSING
With some lenses, red light focuses at a slightly different
point to other visible light. With these lenses there may
be a focus shift when focusing in white light compared
with red light. However, it is almost impossible to focus a
camera with a deep red filter in place.
With short to moderate focal length lenses, this difference
can easily be accommodated by stopping down to the
smallest workable aperture. Some lenses, particularly
apochromatic (APO) designs, may need no correction.

Thank you for the information.
Ok, I think I will take a glow-lamp and focus the lens with the filter on some distances to mark a scale on my camera. I'll focus on the sun to get infinity focus._________________MFRFFC

Don't look directly at the sun, only at the image of it on the ground glass and then only from an off center position.
The filter you are using seems to approximate the "sun screen" used on mariner's sextants used for celestial navigation which required viewing an image of the sun in order to determine the exact angle between the sun and the sea horizon.
BTW I'm the "other Henry" not the same one as posted an earlier reply!